Semiconductor devices formed using graphene and carbon nanotubes expected as low resistance wiring materials have currently been developed. In the semiconductor devices, when graphene is used as a wiring layer material and a CNT is used as a contact member, a catalytic layer, a foundation layer, etc., is inevitably interposed between the wiring layer and the contact in the prior art methods. Therefore, the contact resistance between the wiring layer and the contact is high although the materials of the wiring layer and the contact are sufficiently low in resistance, which makes it difficult to realize low resistance wiring.